Add a module for reading configurations from an .ini file

The module returns the database configurations and the corpus file (a
set of PMIDs)
More robust PybPubmedText

Allow the use of PyPubmedText as a module;
Deals with some errors that might be caused by unicode: if a string s
is in unicode, then s is set to s.encode(‘utf-8’);
DB cursors are opened and close within functions;
Database configurations and corpus are configured via ReadConfig module
through commandline arguments.